How do you hold this thing, ...
Just like anyother camera. You hold the lens (and the ) weight with your left hand, same as would with a Big White mounted on a 1D3.
I don't get it. If size is an issue whats wrong with the rebel series, ...
If you "don't-get-it" the camera wasn't designed for you, and your style of shooting. Simple as that. Serious Photo Enthusiasts (SPE) seem to forget that there are other people who buy cameras.
Check-out the size difference between a Rebel 4Ti and the EOS-M here http://camerasize.com/compare/#333,351
Smaller size = less weight "Canon EOS Rebel T4i [575 g] weights 93% (277 grams) more than Canon EOS M [298 g] (*inc. batteries and memory card)." The EOS-M, with the EF-M 22mm f/2.0 STM lens (=36mm FF) is pocketable and the Rebel 4Ti w/ an EF 24mm f/2.8 IS USM (=38mm FF) isn't. It should be a great camera for "street photographers."
And doesn't the lens size cancel out the smaller body size advantage? I guess they will make new lenses for it that are more compact.
Someone at Canon's marketing department seriously screwed-up by posting shots of an EOS-M with a Big White. It sends the "wrong message," the people who buy EOS-M cameras will be as confused as the SPEs seem to be
It all seems gimmicky to me! I wave my sceptical stick at it!
My Sony NEX-5n w/16mm f2.8 is the only camera I use for non-paid work. My big-heavy-bulky Canon DSLRs stay on the shelf if they aren't making me money. I don't need to impress people with the size of my lens